Copolymers containing fluorine are described in European patent No. 212,508. These are polyvinyl alcohols in which the hydroxyl groups have been esterified by a fluorinated fatty acid. These copolymers are used as water soluble binders for aqueous lacquers. These binders are said to provide improved gloss and improved hardness. Aqueous coating compositions from which films can be prepared, having exceptionally good water resistance are described in German published patent specification No. 3,339,212. This is achieved by providing a dispersion containing particles having a structure similar to onion skin. A complicated method is described in the German publication for preparing water resistant films.